CE versus LC for simultaneous determination of amoxicillin/clavulanic acid and ampicillin/sulbactam in pharmaceutical formulations for injections

A rapid, capillary electrophoresis method was evaluated for determination of amoxicillin and clavulanic acid in Augmentin as well as ampicillin and sulbactam in Unasyn preparations for injections. Phosphate–borate buffer at pH 8.66 containing 14.4% sodium dodecyl sulfate was used as a mobile phase. The method was validated. Reproducibility, precision, accuracy and assay linearity in concentration of amoxicillin 0.05–3.03 mg/ml and ampicillin 0.05–3.08 mg/ml, as well as clavulanic acid 0.02–2.02 mg/ml and sulbactam 0.05–2.08 mg/ml were established. This new method is fast, inexpensive and limits consumption of organic solvents when compared with alternative high performance liquid chromatography (HPLC) method, used for drug analysis. Statistical analysis by Student's t-test showed no significant differences between the results obtained by the two methods t calculated 0.32 and 1.69 for amoxicillin and clavulanic acid and 0.67 and 1.93 for ampicillin and sulbactam were smaller than t tabulated.